Doorbell



FIG. 1 is a front perspective view of a doorbell showing our new design;

FIG. 2 is a rear perspective view thereof;

FIG. 3 is a front elevational view thereof;

FIG. 4 is a rear elevational view thereof;

FIG. 5 is a left-side elevational view thereof;

FIG. 6 is a right-side elevational view thereof;

FIG. 7 is a top plan view thereof; and,

FIG. 8 is a bottom plan view thereof.

The broken lines, the areas outside of the outermost claimed circles on the front face, and the area inside the inner most claimed circle on the bottom of the front face, form no part of the claimed design. 

CLAIM The ornamental design for a doorbell, as shown and described. 